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Publications

Publications by Hélder Filipe Oliveira

2017

Prediction of Breast Deformities: A Step Forward for Planning Aesthetic Results After Breast Surgery

Authors
Bessa, S; Zolfagharnasab, H; Pereira, E; Oliveira, HP;

Publication
PATTERN RECOGNITION AND IMAGE ANALYSIS (IBPRIA 2017)

Abstract
The development of a three-dimensional (3D) planing tool for breast cancer surgery requires the existence of proper deformable models of the breast, with parameters that can be manipulated to obtain the desired shape. However, modelling breast is a challenging task due to the lack of physical landmarks that remain unchanged after deformation. In this paper, the fitting of a 3D point cloud of the breast to a parametric model suitable for surgery planning is investigated. Regression techniques were used to learn breast deformation functions from exemplar data, resulting in comprehensive models easy to manipulate by surgeons. New breast shapes are modelled by varying the type and degree of deformation of three common deformations: ptosis, turn and top-shape.

2015

Video Analysis in Indoor Soccer using a Quadcopter

Authors
Ferreira, FT; Cardoso, JS; Oliveira, HP;

Publication
ICPRAM 2015 - Proceedings of the International Conference on Pattern Recognition Applications and Methods, Volume 1, Lisbon, Portugal, 10-12 January, 2015.

Abstract
Automatic vision systems are widely used in sports competition to analyze individual and collective performance during the matches. However, the complex implementation based on multiple fixed cameras and the human intervention on the process makes this kind of systems expensive and not suitable for the big majority of the teams. In this paper we propose a low-cost, portable and flexible solution based on the use of Unmanned Air Vehicles to capture images from indoor soccer games. Since these vehicles suffer from vibrations and disturbances, the acquired video is very unstable, presenting a set of unusual problems in this type of applications. We propose a complete video-processing framework, including video stabilization, camera calibration, player detection, and team performance analysis. The results showed that camera calibration was able to correct automatically image-to-world homography; the player detection precision and recall was around 75%; and the high-level data interpretation showed a strong similarity with ground-truth derived results.

2013

Methods for the Aesthetic Evaluation of Breast Cancer Conservation Treatment: A Technological Review

Authors
Oliveira, HP; Cardoso, JS; Magalhaes, A; Cardoso, MJ;

Publication
CURRENT MEDICAL IMAGING

Abstract
Breast-conserving approaches aim to attain better aesthetic results in addition to local control and achieving survival rates equivalent to mastectomy in patients with breast cancer. While the oncologic outcome of breast conservation procedures is easily estimated objectively by disease-free and overall survival rates, the cosmetic outcome has no standard of evaluation. Although breast conservation techniques have been widely studied, different forms of evaluation and heterogeneous working practices have contributed to different aesthetic results. As this scenario suggests, the evaluation of aesthetic results should be mandatory in any institution performing breast cancer treatment, contributing to the improvement of current strategies by enabling the identification of variables which have a significant impact on the final aesthetic result. In the process of assessing cosmetic outcomes there are several important issues that should be considered: which factors have a crucial impact on the cosmetic outcome of Breast Cancer Conservation Treatment (BCCT); which parameters or features should be evaluated in the cosmetic assessment of BCCT; how patients are evaluated; which scales are used in this evaluation; which methods and technological solutions are available for the evaluation of cosmetic results of BCCT. In this paper we try to discuss all these questions, with an emphasis on the objective methods and corresponding technologies used in the aesthetic evaluation of BCCT. The most relevant publications related to the mentioned topics are presented, critically analysed and put in chronological perspective. Current and future trends are also discussed.

2014

MobILive 2014-Mobile Iris Liveness Detection Competition

Authors
Sequeira, AF; Oliveira, HP; Monteiro, JC; Monteiro, JP; Cardoso, JS;

Publication
2014 IEEE/IAPR INTERNATIONAL JOINT CONFERENCE ON BIOMETRICS (IJCB 2014)

Abstract
Biometric systems based on iris are vulnerable to several attacks, particularly direct attacks consisting on the presentation of a fake iris to the sensor. The development of iris liveness detection techniques is crucial for the deployment of iris biometric applications in daily life specially in the mobile biometric field. The 1st Mobile Iris Liveness Detection Competition (MobILive) was organized in the context of IJCB2014 in order to record recent advances in iris liveness detection. The goal for (MobILive) was to contribute to the state of the art of this particular subject. This competition covered the most common and simple spoofing attack in which printed images from an authorized user are presented to the sensor by a non-authorized user in order to obtain access. The benchmark dataset was the MobBIOfake database which is composed by a set of 800 iris images and its corresponding fake copies (obtained from printed images of the original ones captured with the same handheld device and in similar conditions). In this paper we present a brief description of the methods and the results achieved by the six participants in the competition. © 2014 IEEE.

2013

Robust Iris Localisation in Challenging Scenarios

Authors
Monteiro, JC; Sequeira, AF; Oliveira, HP; Cardoso, JS;

Publication
Computer Vision, Imaging and Computer Graphics - Theory and Applications - International Joint Conference, VISIGRAPP 2013, Barcelona, Spain, February 21-24, 2013, Revised Selected Papers

Abstract
The use of images acquired in unconstrained scenarios is giving rise to new challenges in the field of iris recognition. Many works in literature reported excellent results in both iris segmentation and recognition but mostly with images acquired in controlled conditions. The intention to broaden the field of application of iris recognition, such as airport security or personal identification in mobile devices, is therefore hindered by the inherent unconstrained nature under which images are to be acquired. The proposed work focuses on mutual context information from iris centre and iris limbic and pupillary contours to perform robust and accurate iris segmentation in noisy images. The developed algorithm was tested on the MobBIO database with a promising 96% segmentation accuracy for the limbic contour.

2016

The breast cancer conservative treatment. Cosmetic results - BCCT.core - Software for objective assessment of esthetic outcome in breast cancer conservative treatment: A narrative review

Authors
Cardoso, MJ; Cardoso, JS; Oliveira, HP; Gouveia, P;

Publication
COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE

Abstract
Background and objective: Cosmetic outcome of breast cancer conservative treatment (BCCT) remains without a standard evaluation method. Subjective methods, in spite of their low reproducibility, continue to be the most frequently used. Objective methods, although more reproducible, seem unable to translate all the subtleties involved in cosmetic outcome. The breast cancer conservative treatment cosmetic results (BCCT. core) software was developed in 2007 to try to overcome these pitfalls. The software is a semi-automatic objective tool that evaluates asymmetry, color differences and scar visibility using patient's digital pictures. The purpose of this work is to review the use of the BCCT. core software since its availability in 2007 and to put forward future developments. Methods: All the online requests for BCCT. core use were registered from June 2007 to December 2014. For each request the department, city and country as well as user intention (clinical use/research or both) were questioned. A literature search was performed in Medline, Google Scholar and ISI Web of Knowledge for all publications using and citing "BCCT.core". Results: During this period 102 centers have requested the software essentially for clinical use. The BCCT. core software was used in 19 full published papers and in 29 conference abstracts. Conclusions: The BCCT. core is a user friendly semi-automatic method for the objective evaluation of BCCT. The number of online requests and publications have been steadily increasing turning this computer program into the most frequently used tool for the objective cosmetic evaluation of BCCT.

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